Copper-Nickel Sulfide Ore-Bearing Formations

Abstract The sulfide copper-nickel deposits of the Noril’sk region (Noril’sk I, Talnakh, Octyabrskaya) were formed during the late Paleozoic to early Mesozoic episode of basaltic extrusion. Spatially and genetically they are related to a group of ultramafic/mafic layered intrusions, and they consist of different types of ores that were formed at different stages. The history of the study of the Noril ‘sk deposits can be considered as a half-century succession of discussions devoted to the source of the ore materials and to the conditions of formation of the mineralization. The most reliable genetic hypothesis is that of the primary magmatic nature of the ore formation as originally proposed by V.K. Kotulsky and M.N. Godlevsky. The copper-nickel deposits of the Noril’sk region are attributed to the development of a volcanic-intrusive ore-magmatic association. On the basis of their overall geologic-petrologic characteristics and structural-tectonic setting [28], these deposits can be regarded as an independent event. The major distinguishing characteristic of these deposits is the interconnected development of the ultramafic/mafic and similar (with respect to composition) komatiitic volcanic rocks and layered intrusive complexes which contain disseminated and massive copper-nickel mineralization. The deposits were formed at particular stages in the development of cratons and ancient platforms, and they occur in regions of intercontinental rifting. The major ore-bearing locations in the greenstone belts of Archean cratons (such as Wiluna-Norseman in Australia, the Rhodesian craton in Zimbabwe etc.), the deposits of the Pechenga ore-bearing region in the Pechenga-Imandra-Varzuga belt of the Baltic shield; and the Noril’sk ore-bearing